The prior art recognizes the advantages of spray type low volume sprinklers, sometimes called microsprayers or microsprinklers, compared to larger rotary, impact, or conventional pop-up sprinklers and small drip emitters. Low pressure systems that operate in the 20 to 30 psi range are more energy efficient since they deliver smaller amounts of water to just the locations where it is needed. This is better than pumping high pressure large volumes of water wastefully over large areas. The low application rates of low pressure systems provide better soil penetration and less runoff. The controlled water placement allows water to be delivered directly to just the plant that needs it, not broadcast over wide areas. Hence, trunks, foliage, and traffic areas remain dry. This saves on water as well. The lower operating pressures and flow rates saves money on pumping energy. Erosion is reduced with microsprinklers. They spread water evenly over the root zone of a plant, simulating natural rainfall. By contrast, a drip emitter soaks one spot for a longer time which tends to leach the soil and decrease soil aeration.
Prior art spray type microsprinklers generally produce one spray pattern each and thus must be available in a variety of different spray pattern types so as to optimally spray water exactly where desired. Typically, a low volume irrigation system is custom planned in advance to serve a particular collection of plants, with the correct spray head chosen for each location in the garden. One suffers the inconvenience, therefore, of having to select new spray heads if the garden is changed or if a mistake is made. The user inevitably ends up paying for extra unused sprinklers and parts. The present invention overcomes this problem by providing a novel multipurpose spray head that allows a plurality of desired spray patterns to be generated by a single microsprayer.